3000 Series A/C Issues

[GreenMtns]

Well the "ole" catch 22. Contact John Deere and they will advise you to contact the dealer. I would suggest going to another dealer and trying another tractor like yours on a hot day. This would give you a reference point. I would then by pass the service department and talk to the manager/owner and explain to him that your unit is not performing like other units and ask that it be corrected.

I think Gator6x4 has the right idea. Check out another one at another dealers. I have run mine at 96 degrees and if the blower is on high I have to put a shirt on. Yours should be cooling as well. You might ask when the area rep will be around and speak with him. Something is wrong with yours since the rest of us are getting a lot more cooling than you are. Your dealer should want to find the problem as well. You have just spent a lot of money there and he should want you happy.
40 hours seems like a lot of time spent on it. That would equal one mechanic for a whole week on this and you still did not get cooling like you should have.

 

[ddivinia]

It sounds like time to write John Deere and ask for help. Get JD engineering involved or something. It sounds like your dealer is trying but doesn't have the expertise to work on it.

D.

 

[sunnyside360]

I have the exact same 3720 tractor and have felt the A/C is somewhat marginal on mine. Today I took some measurements with a digital meter with thermocouple which is pretty straight forward. Anyone having a 3x20 cab tractor can do this fairly quick if they are interested in this A/C issue. It would be good to know the same data for those that are happy with their A/C as well just for comparison and further understanding the issue.

1. Outside weather conditions -- cloudy and 86 deg F

2. Set A/C on MAX cold with de-icer ON and run for 10 mins at 1500 RPM

3. Air vent temps measured from 72 to 74 deg F (coldest when compressor on)

4. Cab temp at center of steering wheel varied from 78 to 80 deg F

As you can see the temp drop between the outside air and at the inside air vent is 12 to 14 deg F. This is an important figure when trying to determine if an A/C unit is functioning properly according to specification. In this case we do not know the spec but John Deere does. However, we can also compare data between tractors with A/C running well and those with A/C not running so well and use it as appropriate with dealer and/or John Deere.

Also did the plastic wrap test at air inlet as suggested above. With the fan on the lowest setting, there was enough negative pressure (vacuum) to suck the plastic wrap into the vent which hopefully discounts any other major air leaks.

 

[Silver_Knight]

I did some more testing today and here is what I found out:

1. Outside temp: 98 F

2. A/C set on coldest position with blower knob set on middle speed 1700-2200 RPM

3. Air vent temp measured from 70.5F to 72.5F

4. When blower speed increased to high vent temp would rise to 74-77F. A few minutes after decreasing speed of blower the vent temp would decrease to around 72.

Did the plastic wrap test and it sucked it in just fine. After running the shredder for an hour I got of and when I slammed the door shut I noticed a pretty big puff of dust come out of the back of the tractor where the filter is. Slammed it 5 more times and it puffed every time. Started the day with a new filter.

Did not notice much change in temp with RPM change.

Although I still do not believe the temps are great, or even good, especially on high, I guess I'll just keep the blower on medium and live with it.

 

[nmu98]

I just got my new cabbed 3720 last night. Took the top off to put in the radio.... 4 large holes in the sealer strip. Looks to be ripped. Mine sucked in the saran wrap too... but i could also feel the leaks before i took the top off....

 

[Labrat]

Take the thermocouple and zip tie it to the suction (large) line returning to the compressor. It would be good to insulate it and have it on the metal part of the line not the rubber part. Also, if you can get it close to the evap it would be better. The suction temp should be between 5 and 10 DEGF lower than supply air temp. If the delta is significantly higher than that you are probably bypassing evap air.

 

[sunnyside360]

I did some more testing today and here is what I found out:

1. Outside temp: 98 F

2. A/C set on coldest position with blower knob set on middle speed 1700-2200 RPM

3. Air vent temp measured from 70.5F to 72.5F

4. When blower speed increased to high vent temp would rise to 74-77F. A few minutes after decreasing speed of blower the vent temp would decrease to around 72.

Did the plastic wrap test and it sucked it in just fine. After running the shredder for an hour I got of and when I slammed the door shut I noticed a pretty big puff of dust come out of the back of the tractor where the filter is. Slammed it 5 more times and it puffed every time. Started the day with a new filter.

Did not notice much change in temp with RPM change.

Although I still do not believe the temps are great, or even good, especially on high, I guess I'll just keep the blower on medium and live with it.

Seems your A/C is working better than mine since you are getting around 26 to 28 deg temp drop between outside air (98) and inside air vents (70 to 72). I agree RPM's don't seem to make much difference. I'll try the "door slam" test and watch for dust cloud. I check/clean my filter quite often during summer months as a dirty filter will drop A/C efficiency.

 

[sunnyside360]

Although not much new to report I did the same measurements again this morning as suggested above.

1. Outside weather conditions -- sunny and 83 deg F

2. Set A/C on MAX cold with de-icer ON and fan on medium @ 1500 RPM

3. Air vent temps measured from 68 to 72 deg F - compressor on @ 72 & off @ 68.

I also slammed the door and watched for cloud of dust at rear and did not see any -- not surprised as filter was recently cleaned and haven't run in dusty conditions since.

 

[Nuru]

I am going in this morning and check out the seal, I am gonna take the top off first, and see what I can see. I am also exploring for a potential radio installation, but I have not decided on that yet. I am leaming towads portable or semi-portable SAT RADIO. SEMI Portable as in, installing an aftermarket radio/CD/DVD? combo with an auxlliray input, and use my small portable Sirius sportster and just plug it in when i want to run SAT Radio. i will post picks if I go with the new radio and auxillary input.

 

[nmu98]

Nuru, Watch the AC and heat control wires, and as you tighten the top down, make sure they work freely. One of them is help in place by a putty. My dealer warned me that that one likes to move to a place where it will bind if you dont watch it. I did not have that issue with mine, but i was very carefull to keep it in place.

My AC works like a champ with the new seal. I had to turn it off on an 85 degree day with sun. It was so cold in the cab I was getting a headache.

 

[radman1]

I checked my a/c this am with infrared thermometer. (Harbor Freight special for $29 and works great.) Outside temp 91F. Operated tractor in the full sun for about 30 minutes. All vents open, max a/c with fan on high. Vent temps varied from 51-55F. Temp in center of cab at steering wheel surface was 76F. Even at these readings, I don't feel the cab is over all too cold. If your getting vent temps in the 70s, I would be complaining and it needs to be fixed.

 

[Nuru]

Nuru, Watch the AC and heat control wires, and as you tighten the top down, make sure they work freely. One of them is help in place by a putty. My dealer warned me that that one likes to move to a place where it will bind if you dont watch it. I did not have that issue with mine, but i was very carefull to keep it in place.

My AC works like a champ with the new seal. I had to turn it off on an 85 degree day with sun. It was so cold in the cab I was getting a headache.

Thanks for the warning, I have them off right now, and when i go back in, I will make sure they are not binding. I am taking the headliner with me to Best Buy and see what they have that I might want and will fit.

I took the top off and I found one break, and one starting to tear. I took pics and wil send to the dealer for proof of need of a replacement seal, and await the replacement seal. In the meantime, I repair the seal as best I could and re-installed the top.
'
Well back to the Headlner!

 

[Silver_Knight]

I checked my a/c this am with infrared thermometer. (Harbor Freight special for $29 and works great.) Outside temp 91F. Operated tractor in the full sun for about 30 minutes. All vents open, max a/c with fan on high. Vent temps varied from 51-55F. Temp in center of cab at steering wheel surface was 76F. Even at these readings, I don't feel the cab is over all too cold. If your getting vent temps in the 70s, I would be complaining and it needs to be fixed.

Radman1, man that's just wrong! Here am am almost satified that I get 70 degrees out of mine and you post that you get 51-55 on a 91 degree day.

I guess I'm getting Deere involded now. If you can get it I should be able too.

 

[radman1]

Did another a/c test. Outside temp is 98F. (More like Texas!) Vent temps in full sun were 54-59F. Steering wheel surface 76-77.
I did notice when you first turn on the a/c and it is hot, it took about 30 min to get these temps. There is a lot of hot surface area to cool down and it takes a while to cool the air box. If I get in and out of the cab a few times it also takes awhile to recover.
It also seemed to cool faster if I left the fan in the middle setting rather than on high when first started. This may allow air box to cool faster? May just be my imagination.
I would still recommend you try clamping off the heater hose to the cab as an additional aid. I installed a valve and have mine turned off. You may also want to get a smoke stick. These are used in houses to check for leaks around windows, electrical outlets. Try one of these around the air box when there is no wind or inside a shed. See if there is an air leak in the air box seal. It should suck in the smoke if there is a leak.
Something else to consider is tinting the cab windows. I have thought about doing this at times. The cab is essentially a green house and tough to cool. It makes sense to me that all cabs should have factory tinted windows except the front.

 

[Silver_Knight]

Here is what I did today while it was 103 outside and sunny.

While in the shade I tried clamping the heater hose and at first I thought I was able to see a difference, after further investigation I could not tell a difference.

I did some shedding and the digital thermo said mid to low 70s.

Next i took the rear filter off and used aliminum duct tape over the air inlet replaced the filter and cover to protect the tape from branches. This basically turned the unit into a recirculating system. I noticed a very significant change. I was able to get the vent temp to 57.4F on medium speed and about 60-61 on high.

All of this was in the shade. As soon as I went into the sun it did increase about 4 degrees on each level.

I think the cab is a little more comfortable (less humid & cooler) with the tape covering the outside air inlet. I wonder how this would effect anything long term?

I did not notice a change in airflow.

 

[radman1]

I think we can eliminate the heater as a problem. I still wonder if there is a problem with a leak in the air box. I think you should try blocking off the outside filter and then check with a smoke stick (extinguished candle or match) to see if air is being sucked in where it shouldn't. With the filter blocked off, your readings are similar to mine. I had a leak in my air box that was very hard to see by the dealer. It wasn't a leak at the air box seal. It was nearly completely hidden in the corners.

 

[Silver_Knight]

Would a leak in the seal/air box blow air out or suck air into cab?

 

[Willis Fecon Bushhogging]

Would a leak in the seal/air box blow air out or suck air into cab?

I think you said the condensor was clean, but what I learned the hard way, was I was using a strong pressure water hose, to clean out the radiator and condensor, then I would go to work, the dust/dirt would then get stuck like mud in the condensor/radiator. Yes, I know what dummy does that, but it was a learning process and I learned to use air pressure, or if I used water at anytime, I would let it dry overnight. If you dont have good air flow through the radiator the A/C will have a problem cooling. Does the A/C compressor cut on and off-on and off-on and off? Im assumming someone has checked the freon pressure.
I had a pickup that I spent about $700 on the A/C system and it still wouldnt cool, come to find out it was the inline filter, I didnt think it had one, but it doesnt look like a filter and it took a special tool to get it out, but I was there when it came out and it was stopped up, replaced it and now its about 50 degrees, a $10 part cost me $700, live and learn

 

[radman1]

Would a leak in the seal/air box blow air out or suck air into cab?

Leak will suck air in. Too much outside hot air coming in and the a/c can't cool it fast enough. Check your air filter also to make sure it doesn't have a tear or poor seal and letting too much air in.

 

[Silver_Knight]

Leak will suck air in. Too much outside hot air coming in and the a/c can't cool it fast enough. Check your air filter also to make sure it doesn't have a tear or poor seal and letting too much air in.

Radman1, I have taped the filter inlet completely where no airflow from the ooutside comes in at the air filter inlet. I will try the smoke test tomorrow.